In a letter-to-the-editor, we argue that the outcomes are invalid because of the low quality and heterogeneity of the studies included. Vowles et al. included 38 studies and many of these had been rejected in a Cochrane study by Minozzi et al. on their determination that the studies were not adequate for the purposes of a meta-analysis (2),(3). Moreover, definitions used by the authors are vague.
Amazingly, the authors’ definition of misuse is “opioid use contrary to the directed or prescribed pattern of use, regardless of the presence or absence of harm or adverse effects”. This is identical to what is generally called patient non-compliance, a common problem in patients to whom medicines are prescribed. Therefore, putting a figure on non-compliance among opioid analgesic patients only makes sense if comparing to non-compliance rates for all medicines, which is 25 %(4). Therefore, non-compliance (‘misuse’) in patients using opioid analgesics is not any different from non-compliance among the general population of patients who use medicines.
Also the analysis of addiction rates is not a reliable outcome and contrary to what Vowles et al. suggest, according to the Cochrane study by Minozzi et al., there is not any reason to withhold opioid analgesics to pain patients in need.
Moreover, in a Special Commentary in the same issue of PAIN, Dr Jane Ballantine says that the authors “tackle the debatably impossible task of estimating the prevalence of opioid misuse, abuse, and addiction in chronic pain”, but simultaneously, she admits that “it is hard to understand what addiction actually is when it arises during pain treatment with opioids.” Then she commends that “All patients exhibiting misuse, abuse, or addiction” should be included in “addiction-type programmes”(5).
It is always good for a doctor to look critically on his or her own prescribing habits, to assess the pain as good as possible and then, to prescribe the correct amount of the best medicine at the right dosage. Sometimes this could even mean that another option than pharmacological treatment is preferred. However, basing oneself on unfounded and incredibly high figures of misuse and dependence is not in the interest of the patients and therefore, a health abuse.
The letter-to-the-editor can be accessed via the PAIN website.
Please contact Willem Scholten for any correspondence at wk.scholten @ xs4all.nl
1. Vowles KE, Mindy L. McEntee ML, Peter Siyahhan Julnes PS, Frohe T, Ney JP, Van der Goes DN. Rates of opioid misuse, abuse, and addiction in chronic pain: a systematic review and data synthesis. PAIN, April 2015; Vol 15(4): 569-576.
2. Scholten W, Henningfield JE. A meta-analysis based on diffuse definitions and low quality literature is not a good fundament for decisions on treatment of chronic pain patients. PAIN, August 2015; 156(8): 1576-1578
3. Minozzi S, Amato L, Davoli M. Development of dependence following treatment with opioid analgesics for pain relief: a systematic review. Addiction. 2013 Apr;108(4):688-98.
4. DiMatteo MR. Variations in patients’ adherence to medical recommendations: a quantitative review of 50 years of research. Med Care. 2004;42:200–209.
5. Ballantyne JC. Assessing the prevalence of opioid misuse, abuse, and addiction in chronic pain. PAIN, April 2015; Vol 15(4): 567-568.